The long range goal of this research is to elucidate potential biological mechanisms whereby hostility contributes to increased risk of coronary heart disease. Preliminary findings already have shown that, in contrast to women with low scores on the Cook and Medley Hostility (Ho) scale, women with high Ho scores exhibit greater cardiovascular changes to harassment. Additional findings have suggested that oral contraceptive (0C) use may also be associated with increased behaviorally-induced physiological changes, especially in low Ho women. Similarly, higher levels of total serum cholesterol (TSC) have been positively associated with greater stress-induced neurohormonal changes in middle-aged men with high Ho scores. Given that hostility, lipids, and 0C use have been associated with increased risk of disease, the aim of these studies is to determine the combined effects of hostility, harassment, lipids, and 0C use on physiological responses in young and middle-aged premenopausal women. Assessment of autonomic activity will take place in the laboratory and during an 24 our ambulatory measurement period. The laboratory assessment will help to determine if high Ho women respond to harassment with greater cardiovascular and neurohormonal changes than low Ho women, and if this relationship is altered by 0C use, lipids, and age. The ambulatory assessment of autonomic activity will allow for an exploration of the responses of high and low Ho subjects to daily-life stressors. Several hypothesis will be explored: 1) Does harassment produce neuroendocrine as well as cardiovascular hyperreactivity in young women, and does this hyperreactivity generalize from laboratory to real-life? 2) Is the harassment-induced cardiovascular and neuroendocrine changes that we expect to see in young women also present in middle-aged women? 3) To what extent does 0C use modulate the cardiovascular and neuroendocrine responses to harassment in young women, and is 0C use also altering the hostility-- related associations between lipids and reactivity? 4) Are the differential lipid-reactivity associations observed in middle-aged men as a function of high and low Ho scores present in women, and, if so, are they modulated by age? These studies will extend our understanding of pathogenic mechanisms of hostility to women who, though subject to the deleterious health effects of hostility, have not been studied extensively in reactivity research.